WO2010028737A1

WO2010028737A1 - Exterior surface component, particularly a hood

Info

Publication number: WO2010028737A1
Application number: PCT/EP2009/005976
Authority: WO
Inventors: Jürgen CORDES; Thomas Ehlers; Thomas Pörtner; Olaf Insel; Jürgen Stein; Thomas Drescher; Michael Rund; Kai-Uwe Kriszun; Volker Schriever
Original assignee: Volkswagen Aktiengesellschaft
Priority date: 2008-09-12
Filing date: 2009-08-18
Publication date: 2010-03-18
Also published as: DE102008046910B4; DE102008046910A1

Abstract

The invention relates to an exterior surface component, particularly a hood, for motor vehicle bodies, having a substantially thin-walled exterior surface component forming the vehicle curve, a frame part fixedly connected to the exterior part and disposed below the same and along the outer contour, and a reinforcement structure disposed therebetween. In order to obtain a particularly effective crash absorption in collisions, the invention proposes that the frame (3) is connected to the exterior part (2) and the reinforcement structure (4), such that said frame substantially only ensures the rigidity of the exterior component (1), and that crash energy acting substantially vertically or diagonally on the surface of the exterior part (2) is absorbed nearly exclusively by the exterior part (2) and the reinforcement structure (4).

Description

description

Flat external component, in particular front hood

The present invention relates to a flat exterior component, in particular a front hood, for bodies of motor vehicles, according to the preamble of claim 1.

DE 100 59 759 A1 describes a front hood for bodywork of motor vehicles, which is designed for improved absorption of impact energy with a flat outer part, a U-shaped open to the rear frame and a stiffening structure arranged therebetween. The stiffening structure consists of several struts, which are connected via a solid, deformable foam with the outer part and partially structurally form the frame. The purpose of the proposed construction is, inter alia, to improve the pedestrian protection of the motor vehicle and in particular to reduce the head injury criterion (HIC) in the region of the stiffening structure. Since the stiffening structure of the front hood goes into their frame, but not only the relevant deformation values (HIC values), but also the general stiffness of the bonnet must be considered.

The object of the invention is to meet the different requirements in general strength and the damping of impact energy in particular to a flat exterior component, in particular on a front hood for bodies of motor vehicles, in still improved extent.

This object is achieved with the characterizing features of claim 1. Advantageous further embodiments of the invention can be found in the dependent claims.

According to the invention, it is proposed that the frame is connected to the outer part and the stiffening structure such that it essentially ensures only the rigidity of the outer component and that substantially perpendicular or oblique impact energy is absorbed almost exclusively by the outer part and the stiffening structure on the surface of the outer part becomes. In other words, the impact energy of the outer part and the stiffening structure is at least 90% added. It is proposed in terms of keywords to largely separate the framework and the stiffening structure in their functions. While the correspondingly executed frame ensures rigidity which is commensurate with the usual operating loads of the outer component or the front hood, the impact energy in the event of a collision can satisfactorily cushion the function and sufficient buckling rigidity of the outer part and the underlying stiffening structure, the structural design thereof can be done with more degrees of freedom.

In a preferred manner, the frame can at least predominantly have a closed hollow profile and run around the entire outer part. Such a closed frame achieves high rigidity even with small dimensions and wall thicknesses, e.g. in a front hood, the hinge support whose pivot bearing and the locking mechanism of a hood lock can be easily connected to the frame.

In a particularly advantageous manner, the frame may extend at least partially at a defined distance below the outer part and be connected only via an upwardly parked flange with the outer part. On the one hand, this results in an effective decoupling in the said different demands on the outer component and ensures an additional deformation path or even an improved impact damping almost over the entire outer surface of the outer part.

In a conventional manner, the connection between the frame and the outer part can be largely accomplished by flanging the outer part to flanges of the frame. Further, additional adhesive bonds may be provided between the frame and the outer member at higher permanently loaded locations of the frame (e.g., in the latching portion and at the hinge portions).

In terms of manufacturing technology, the peripheral frame may be formed by a lower profile sheet and an upper strike plate which are connected to one another in a materially bonded manner, in particular by electrical resistance welding or spot welding.

Furthermore, in an advantageous embodiment, the hollow profile of the frame may be at least partially executed such that the upper strike plate extends obliquely downward from the outer contour of the outer part by increasing the defined distance to the outer part. This results in an increasing to the center of the outer part Deformation path between the flat outer part and the underlying frame and thus also contributes to an improved reduction of impact energy. The peripheral frame can be made by means of a sheet metal blank. For reasons of better material use of the sheet metal blank, the peripheral frame may be formed by a plurality of frame members, which are fixed to each other - in particular by spot welding.

In this case, the frame may preferably be subdivided into four frame spars, which are connected to each other substantially longitudinally and transversely in the region of their respective change in direction.

Furthermore, the connecting region outside the bend can expediently be provided in each case when the direction of change of the frame members is bent substantially by 90 degrees. In particular, with overlapping connection areas, a simple tolerance compensation between the frame beams can thus be produced.

Furthermore, connecting portions of the frame members overlap by staggered notches in the lower profile sheet and / or in the striking plate can overlap one another in the frame longitudinal direction and thus additionally increase the rigidity of the frame with low manufacturing overhead. It can also be provided on notches in the connection region of the lower profile sheet and / or the strike plate in the cavity of the frame projecting stiffening flanges.

In an advantageous embodiment of the invention, the stiffening structure can be formed within the frame by a grid structure with longitudinal and transverse struts, which can be adapted to the required damping properties and the deformation behavior by the number of struts, their distances from one another and their configuration excellent and relatively is easy to produce.

Preferably, the struts of the grid structure may have an approximately hat-shaped cross-sectional profile and be arranged open at the bottom, wherein the struts are firmly connected by means of adhesive bonds with the outer part. In this case, the base portion of the struts can be made curved relative to the outer part and glued to the outer part substantially linearly via an adhesive bead applied along the struts. The struts are accordingly facing down or away from the flat outer part open executed and only with her Base section connected linearly with the outer part. This results in a greater flexibility of the grid structure in itself or a more uniform, impact-related damping effect over a predetermined deformation path of the outer part.

In order to simplify assembly and improve process reliability, the grid structure can furthermore be connected to the struts by means of tabs aligned in the longitudinal and transverse directions, wherein the tabs are oriented such that they are largely ineffective in the direction of the impinging impactor or absorb no impact energy.

Finally, in the corner regions of the frame at the lower profile sheet and / or strike plate widening cover plates can be formed with sealing portions for underlying body parts. The cover plates may in the case of a front hood, e.g. Seal the water tank of the heating and / or air conditioning of the motor vehicle relative to an engine compartment lying in front.

An embodiment of the invention is explained in more detail below with further details. The schematic drawing shows in:

Figure 1 is a plan view of a front hood for bodies of motor vehicles, which consists of a only partially shown, flat outer part, a frame extending around its outer contour and a stiffening structure.

FIG. 2 shows a section along the line II-II of FIG. 1 through the frame of the front hood; FIG.

Figure 3 is a transverse section along the line III - III of Figure 1 through the entire front hood.

4 shows a further, longitudinal section along line IV -IV of Figure 1 through the entire front hood.

5 shows a plan view of the front hood according to FIGS. 1 to 4, but with the outer part removed and showing the adhesive connections between the lattice structure on the one hand and the frame on the other hand with the outer part; FIG. 6 shows a detail Z according to FIG. 5 of the frame of the front hood in the connection area at the front right with mutually offset notches of the striking plate; FIG. and

Fig. 7 shows a partial cross section along the line VII - VII of Fig. 6 through the frame or its upper strike plate in the illustrated connection area.

In Fig. 1, 1 denotes a flat outer component or a front hood for a body of a passenger vehicle, which consists essentially of a flat, thin-walled and outer outer forming part (or outer skin) 2, an underlying box-shaped frame 3 and a stiffening structure or lattice structure 4 composed. Said components are made of deep-drawn sheet, but could possibly also at least partially consist of plastic components. The outer part 2 is shown only in sections.

The frame 3 is seen to be approximately rectangular in plan view and extends as shown substantially along the outer contour of the outer part 2 and around it, being composed of two longitudinal frame beams 5, 6 and two transverse frame beams 7, 8.

The frame 3 is, as shown in FIGS. 2, 3 and 4, executed with a closed hollow profile and has per frame spar 5, 6, 7, 8, a lower profile sheet 3a and an upper striking plate 3b, which on integrally formed flange portions 3c (see In particular Fig. 2, frame spar 6) are firmly connected by electrical resistance welding or spot welding.

Furthermore, another, upwardly folded edge flange 3d is integrally formed on the profiled sheet 3a, which is firmly connected by crimping the edge portion 2a of the outer part 2 with the outer part 2. The geometry of the edge flange 2a in the plan view also shows the Fig. 1; it essentially corresponds to the outer contour of the outer part 2.

Due to the upwardly parked edge flange 3d, the frame 3 is positioned at least on the longitudinally extending frame struts 5, 6 and on the rear, transversely extending frame spar 8 at a defined distance s to the outer part 2, resulting in an enlarged from the front hood center outward deformation zone results in perpendicular or obliquely applied impact energy. Further, the striking plate 3b of the frame 3 - as shown in particular Fig. 2 - designed to the plane of the outer part 2 obliquely inwardly downwards, so that said distance s of the front hood center to further increases and thus ensures additional deformation path down.

The front frame member 7 of the frame 3 is deviating from the above described and arranged such that no distance s is present or the strike plate 3b in direct contact with the outer part 2 extends. This design is required for reasons of space with respect to underlying body parts of the motor vehicle, but has no adverse effect on the desired impact attenuation, as this downwardly sloping front area is outside the assumed head impact zone and therefore even favorably affects the front deformation behavior of the body.

Not shown manner are attached to the longitudinal frame members 5, 6 of the frame 3 hinge support of a pivotal movement of the front hood 1 enabling hinged to the subsequent body hinges.

Furthermore, the front frame spar 7 of the frame 3 carries a latch bolt (not shown) projecting downwardly, which cooperates with a latch lock on a strike plate of the body of the motor vehicle arranged underneath and holds the front hood 1 in a closed position.

As can be seen from the adhesive plan shown in FIG. 5, adhesive beads 9 (shown hatched) are applied to the longitudinal frame beams 5, 6 and the front frame spar 7 for additional stiffening of the front hood in the region of said hinge support, in addition to the flare connection with the outer part 2 produce an additional adhesive bond.

The adhesive joint 9 is formed in each case between the striking plate 3 b and the outer part 2. In the case of the frame members 5, 6, the striking plates 3b in the area shown (line 9) are designed so that the distance s to the outer part 2 for producing the adhesive connection 9 is correspondingly reduced.

Cover plates 3e are integrally formed on the profiled sheet 3a on the longitudinally extending frame struts 5, 6 and on the transversely extending frame spar 8 (see FIG Cover plate, the left side is a mirror image of the same), which seal an underlying water tank a heating and air conditioning device of the motor vehicle relative to a front engine compartment. The cover plates 3e can wear sealing lips or hose seals, not shown.

The connection areas between the frame beams 5, 6, 7, 8 are made with reference to FIG. 5 as follows:

To connect the frame members 5, 6 with the rear frame spar 8, the frame spar 8 is cut to length outside its approximately 90 ° bend 8a at a joint 10 and fixed in an overlapping manner by spot welding to the adjacent frame beams 5, 6.

To connect the frame members 5, 6 with the front frame member 7 (see Fig. 5 to 7) whose profile plates 3a and closing plates 3b are provided with stepped notches (generally designated 11), which overlap at their edge regions and thus a particularly rigid Represent connection.

6 and 7 show the connection region with the notches 11 on the strike plates 3b of the frame members 5, 7, which are connected together by joining by spot welding 12 firmly together.

In addition, a stiffening flange 3f is formed on the strike plate 3b of the frame Holmes 7 or on the notch 11, which projects bent by about 90 degrees into the cavity of the frame 3.

The connecting region between the longitudinal frame member 6 and the front frame member 7 is mirror-inverted.

The lattice structure 4 of the front hood 1 is composed, as is apparent in particular from FIGS. 1 and 5, from longitudinal and transverse, and at the intersection points interconnected struts 13 and 14 of thin-walled steel together. The struts 13, 14 are punched out of a metal sheet accordingly.

The struts 13, 14 are seen in cross-section approximately hat-shaped with downwardly open profile (see Fig .. 3 and 4) executed. Their base portion 13a, 14a is curved such that they have only one line contact with the flat outer part 2. The lattice structure 4 is firmly connected to the frame 3 via a plurality of longitudinally and transversely arranged lugs 15 of sheet steel. Optionally, the grid structure 4 and the profiled sheet 3a may be formed from a sheet metal blank.

For the preparation of the front hood 1, the procedure is as follows:

First, the lattice structure 4 is produced by punching and corresponding deformation of the struts 13, 14. The tabs 15 can be directly molded or welded to the struts 13, 14.

The frame 3 made of deep-drawn sheet metal is produced by shaping the profiled sheets 3a and the striking sheets 3b. Then, the profile sheets 3a are welded together to form a subframe and the strike plates 3b to a top frame. Thereafter, sub-frames and upper frames are joined to the frame 3 by spot welding joints at their flanges 3c.

Subsequently, this substructure of frame 3 and grid structure 4 are connected to the outer part 2 to the front hood 1.

For this purpose, as shown in Fig. 5 on the said areas of the frame 3, the adhesive beads 9 applied. Furthermore, adhesive beads 16 (shown hatched) are applied to the struts 13, 14 over their longitudinal extent, ie longitudinally and transversely.

Then, the substructure 3, 4 are joined to the outer part 2 in a tensioning device (not shown) and the flare connection 2a is produced.

Finally, the hinge support, not shown, and the said latch and possibly other attachments are attached to the front hood 1. LIST OF REFERENCE NUMBERS

bonnet

Outer part a edge area of the outer part

Frame a profiled sheet b striking plate c flange d edge flange. e Cover plate f stiffening flange

lattice structure

frame spar

Frame rail a bend

Kleberaupe 0 joint 1 notches 2 spot welds 3 struts 3a base section 4 struts 4a base section 5 tabs 6 adhesive beads

Claims

claims

1. Flat outer component, in particular front hood (1), for a body of a motor vehicle, with a vehicle body forming, substantially flat and thin-walled outer part (2), one fixed to the outer part (2), underlying and arranged along the outer contour Frame (3) and an interposed stiffening structure (4), characterized in that the frame (3) with the outer part (2) and the

- Stiffening structure (4) is connected such that it substantially the rigidity of the outer component (1) ensures and that on the surface of the outer part (2) substantially perpendicular or obliquely acting impact energy almost exclusively of the outer part (2) and the stiffening structure ( 4) is recorded.

2. Flat exterior component according to claim 1, characterized in that the frame (3) at least predominantly has a closed hollow profile and extends around the entire outer part (2).

3. A flat exterior component according to claims 1 or 2, characterized in that the frame (3) at least partially with a defined distance (s) below the outer part (2), and / or only via an upwardly parked flange connection (3d) with the outer part (2) is connected.

4. surface external component according to one of the preceding claims, characterized in that the connection between the frame (3) and the outer part (2) by flanging the outer part (2) to flanges (3d) of the frame (3) is accomplished.

5. Sheet-like outer component according to one of the preceding claims, characterized in that at higher permanently loaded points of the frame (3) additional adhesive connections (9) between the frame (3) and the outer part (2) are provided.

6. Flat exterior component according to one of the preceding claims, characterized in that the peripheral frame (3) by a lower profile sheet (3 a) and an upper strike plate (3 b) is formed, which are materially interconnected.

7. A flat external component according to one of claims 2 to 6, characterized in that the hollow profile of the frame (3) is at least partially designed such that the upper striking plate (3b) of the outer contour of the outer part (2) away obliquely down under magnification the defined distance (s) to the outer part (2) extends.

8. A sheet-like outer component according to one of the preceding claims, characterized in that the peripheral frame (3) by a plurality of frame members (5, 6, 7, 8) is formed, which are fixedly connected to each other.

θ, Flat exterior component according to claim 8, characterized in that the frame (3) is divided into four frame spars (5, 6, 7, 8), which are interconnected substantially longitudinally and transversely in the region of their respective change in direction.

10. A flat exterior component according to claim 8, characterized in that at substantially kinking by 90 ° change of direction of the frame members (8) of the connecting region (10) outside the bend (8 a) is provided.

11. A flat external component according to one of claims 8 to 10, characterized in that connecting regions of the frame members (5, 6, 7) by staggered notches (11) in the lower profile sheet (3a) and / or in the striking plate (3b) each other in the frame longitudinal direction overlap seen.

12. A flat external component according to claim 11, characterized in that on notches (11) in the connecting region of the lower profile sheet (3a) and / or the closing plate (3b) in the cavity of the frame (3) projecting stiffening flanges (3f) are provided.

13. A flat exterior component according to one of the preceding claims, characterized in that the stiffening structure within the frame (3) by a grid structure (4) with longitudinal and transverse struts (13, 14) is formed.

14. A flat external component according to claim 13, characterized in that struts (13, 14) of the lattice structure (4) have an approximately hat-shaped cross-sectional profile and are arranged open at the bottom, and / or that the struts (13, 14) by means of adhesive joints (16 ) are firmly connected to the outer part (2).

15. Sheet-like outer component according to claims 13 or 14, characterized in that the base portion (13a, 14a) of the struts (13, 14) each with respect to the outer part (2) curved and over a along the struts (13, 14) applied Adhesive bead (16) is glued substantially linearly with the outer part (2).

16. A flat external component according to any one of claims 13 to 15, characterized in that the grid structure (4) with the struts (13, 14) via longitudinally and transversely aligned tabs (15) with the frame (3) is connected.

17. Flat exterior component according to one of the preceding claims, characterized in that in corner regions of the frame (3) on the lower profile sheet (3a) and / or strike plate (3b) widening cover plates (3e) are formed with sealing portions for underlying body parts.

18. Sheet-like exterior component according to one of the preceding claims, characterized in that the stiffening structure (4) is a metal grid structure which is formed of the same material and / or in one piece with the frame (3).

19. A flat attachment according to any one of claims 1 to 17, characterized in that the stiffening structure (4) is a foam structure, a honeycomb structure or a cardboard construction.